Characterization the Mode of Ignition of Laminated Systems, Especially of Plywoods and Fire-retardant Plywoods (I) On the Particular Temperature-profile inside the Plywoods upon Heating and the Mechanism of Fire-retardant, Self-extinguishing potency of Ammonium bromide in the Core

Abstract

Investigation on the mode of violent ignition of Japanese Lauwan plywoods with thin surface veneer and developments of flame-retardant, self extinguishing plywoods with untreated surface-veneer have been pursued.
Estimation on the particular temperature-profile along the glue-lines and inside the core have been pursued by I. B. M. 1620 computer on the basis of non-linear Fourier eq. involving Arrhenius terms.
Particular, extremely high temperature-profile along the first glue-lines have been recognized in the numerical computation just before ignition and inside the core upon heating.
Flame-retardant action of ammonium bromide and organic bromine compound immersed in the core have been recognized as negative catalyser in the vapor-phase combustion with respect to the core-treated and surface-untreated self-extinguishing plywoods.
Flame-retardant potency of the above material have been attributed to the percent of the suppression of heat of combustion ΔH₀ of woodmaterials. The reduced ratio of heat-suppression as represented in terms of ( ΔH₀-ΔH ) /ΔH have been linearly proportional to the logarithm of the concentration of ammonium bromide or its chemical potential in the vapor phase.
The reduced ratio will give 1 Kcal / mol as heat of combustion for the treated system from q=-32 cal / gr in the untreated systems.
The temperature profile experimentally obtained for the treated plywood has been perfectly coincided with those obtained in the numerical computation on the basis of Fourier eq, taking q equal to 1 cal / gr and E equal to 37 Kcal / mol.